Apple on Tuesday was granted a patent for embedding light-sensing sensors directly into device displays, an important step in creating a full-screen iPhone without the trademark "chin and forehead" bezels.

As noted in Apple's U.S. Patent No. 9,466,653 for "Electronic devices with display-integrated light sensors," light-sensing apparatuses are commonly displaced from the device display. While advantageous from a production standpoint, such implementations lead to wasted space, or in some cases force sleek designs to be modified. Indeed, the iPhone's proximity and ALS are positioned above the display near the handset speaker.

In a rethink of contemporary smartphone design, Apple proposes forming sensors on display layers that already boast the conductive traces needed for power. Most embodiments describe a method of overlaying the sensor on top of a display layer in a screen stack, whether it be OLED or LCD. Some embodiments provide for sensor positioning at the periphery of a device display beyond the edge of touch sensitive traces to avoid touch sensitivity issues.

Certain embodiments dispose an ALS or proximity sensor at the extreme edge of an OLED display abutting a touch-sensitive layer, for example. Alternatively, a handset could include a dedicated TFT layer onto which a variety of sensors are embedded. In each case, all display and sensor circuitry is protected by a transparent encapsulation layer made from glass or plastic.

The key to today's patent is the design. In each scenario, the sensor or sensors are disposed within the display itself, not above it as with current iPhone, iPad and Mac models. This design tweak alone would save precious millimeters off final design specifications and could pave the way to a true full-screen display.

Apple is said to be working on an advanced iPhone design with "full-screen face," meaning the rumored OLED display stretches across the device's entirety. Moving closer toward that goal, the company last week patented technology detailing a fingerprint sensor that works through portable device displays. The ear speaker remains a problem, though Apple could theoretically turn to a different audio technology and hide that component under the display as well.

Apple's embedded light sensor patent was first filed for in June 2015 and credits Erik G. de Jong, Anna-Katrina Shedletsky and Prashanth S. Holenarsipur as its inventors.